| Year | Description |
| 1951 | Pumice. |
| 1952 | Island formed. |
| 1953 | Water column several hundred feet high. |
| 1958 | "Flames" seen from ship. |
| 1961 | Island formed. |
| 1964 | Red glow at night. |
| 1965 | Crater rim above sea. |
| 1966 | Ash and steam eruptions. |
| 1969 | Water eruptions seen on 28 October reduced to boiling action by the 31st. |
| 1970 | Water spouts in late December. Cone observed 50 feet above the surface; glowing ash cloud. |
| 1976 | Pilot observes eruption of water and tephra above the surface on 23 August. Island formation on 7 September; lava and block eruptions. Pyroclastic eruptions continue through September. |
| 1977 | Eruptive activity observed in February 1977. |
| 1978 | New island formed. |
| 1980 | Small submarine eruption. |
| 1981 | Submarine activity. Bubbling and discolored water. |
| 1985 | Submarine explosions. |
| 1986 | Continuing submarine activity. |
| 1991 | Submarine eruption builds new island. May-June submarine eruption ends; temporary island eroded away. |
| 1992 | Bathymetric survey reveals gas emission. |
| 1997 | Submarine ejection of mud and hot ash; plumes rise to 2.1 km. |
| 2000 | Scientists on board a research vessel observe a new submarine eruption. |
| 2001 | Daily eruptions August to mid-September 2001; eruption 27 November. |
| 2004 | Ongoing submarine eruptions; shifting summit elevations. |